The present invention relates to door lights, and more specifically to fixed, flush-mounted integral door lights.
A great many door-light constructions have been developed for mounting one or more glass panels within a door. Generally speaking, door lights are of two types--vented or fixed. In a vented door light, one of the glass panels is mounted for sliding movement enabling ventilation through the door. In a fixed door light, the glass panel or panels are stationarily mounted within the door. The present invention relates to fixed door lights.
Recently, fixed door lights have become increasingly popular because of the widespread acceptance of the "patio door". Generally speaking, the patio door is a substitute for the conventional sliding door and has a hinged rather than sliding movement. The door light extends substantially the full height and width of the door with only a relatively narrow rail and stile frame supporting the light. The patio door is typically more energy efficient than a sliding door because air infiltration seals are more effective in hinged doors than in sliding doors.
Fixed door-light constructions have been developed which are specifically for or adaptable to patio doors. Two such constructions are illustrated in U.S. Pat. Nos. 4,430,836, issued Feb. 14, 1984 to McKann and entitled FRAME ASSEMBLY FOR DOOR LIGHT, and 4,413,397, issued Nov. 8, 1983 to McKann entitled METAL DOOR AND LIGHT ASSEMBLY (both apparently owned by General Products Co., Inc. of Fredricksburg, Va.). Both patents disclose a door assembly having a fixed door light supported in the door by a rather complicated frame assembly. Two identical frame halves are installed from opposite sides of the door to entrap the glass panel therebetween. Each frame half is generally U-shaped including a facing portion, a glass-engaging leg extending from the facing portion, and a locator leg also extending from the facing portion. The steel door skins extend inwardly toward one another at the door-light opening and terminate in tabs which extend away from the core of the door approximately midway between the two sides of the door. The locator legs on the frame halves engage these tabs to register or locate the assembly with respect to the door. The locator legs on the frame halves engage these tabs to register or locate the assembly with respect to the door. The glass-engaging legs engage opposite sides of the glass panel to support the panel within the opening. Caulking tape on the glass panel provides a seal between the frame halves and the panel. Although not specifically disclosed, it is believed that the commercial embodiment of this product additionally provides butyl glazing between each frame half and the adjacent steel door skin to provide a weather seal therebetween.
The McKann structure suffers several drawbacks. First, the necessity of applying butyl caulking between each frame half and the adjacent steel door skin complicates manufacture and therefore increases the cost of the door. Second, the thermally conductive metal frame halves require insulating blocks therebetween to provide a construction having an acceptable R-value. Third, a rather complicated fastening structure is required comprising plastic inserts and screws through both frame halves. This further complicates assembly and therefore increases the cost of the product. Finally, the frame assembly requires an excessive number of parts posing manufacturing, inventory, and servicing problems.